require _core_en in handlebars_helper.
require _core_en in handlebars_helper.

fixes CNVS-5317

previously, _core_en was not being required in the
javascript test suite, which broke anything that
relied on the core translation set.

test plan:
  * run `rake js:test` and verify that it passes.

Change-Id: I625a9ea97d6e5e9868f53c8739dfe67534666193
Reviewed-on: https://gerrit.instructure.com/19600
Tested-by: Jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@instructure.com>
Reviewed-by: Jon Jensen <44f878afe53efc66b76772bd845eb65944ed8232@instructure.com>
Product-Review: Bryan Madsen <0a3ba1af216659500dd8f41e29f3979f42452870@instructure.com>
QA-Review: Bryan Madsen <0a3ba1af216659500dd8f41e29f3979f42452870@instructure.com>

utkarshx/canvas-lms,dgynn/canvas-lms,sdeleon28/canvas-lms,HotChalk/canvas-lms,fronteerio/canvas-lms,tgroshon/canvas-lms,narigone/canvas,grahamb/canvas-lms,grahamb/canvas-lms,skmezanul/canvas-lms,SwinburneOnline/canvas-lms,roxolan/canvas-lms,antoniuslin/canvas-lms,efrj/canvas-lms,utkarshx/canvas-lms,whalejasmine/canvas-lms,arrivu/jigsaw-lms,HotChalk/canvas-lms,instructure/canvas-lms,whalejasmine/canvas-lms,matematikk-mooc/canvas-lms,whalejasmine/canvas-lms,sfu/canvas-lms,gbleydon/canvas-lms,arrivu/hoodemo,loganrun/pincan,instructure/canvas-lms,samuels410/greatlakes-lms,va7map/canvas-lms,juoni/canvas-lms,roxolan/canvas-lms,eCNAP/CANVAS,va7map/canvas-lms,wimemx/Canvas,instructure/canvas-lms,arrivu/arrivu-lms,ShreniiNepal/shrenii_lmp,wye0220/shindig-canvas,grahamb/canvas-lms,loganrun/pincan,redconfetti/canvas-lms,venturehive/canvas-lms,sfu/canvas-lms,arrivu/hoodemo,snehakachroo1/LSI_replica,arrivu/qibla-ecampus,greyhwndz/canvas-lms,grahamb/canvas-lms,leftplusrightllc/canvas-lms,venturehive/canvas-lms,ShreniiNepal/shrenii_lmp,Jyaasa/canvas-lms,arrivu/hoodemo,djbender/canvas-lms,usmschuck/canvas,narigone/canvas,Rvor/canvas-lms,kyroskoh/canvas-lms,kyroskoh/canvas-lms,instructure/canvas-lms,wrdsb/canvas-lms,leftplusrightllc/canvas-lms,utkarshx/canvas-lms,Jyaasa/canvas-lms,arrivu/arrivu-lms,greyhwndz/canvas-lms,va7map/canvas-lms,tgroshon/canvas-lms,sfu/canvas-lms,SwinburneOnline/canvas-lms,juoni/canvas-lms,venturehive/canvas-lms,arrivu/jigsaw-lms,merichar/canvas-lms,efrj/canvas-lms,greyhwndz/canvas-lms,snehakachroo1/LSI_replica,redconfetti/canvas-lms,sli7246/canvas_branch,arrivu/qibla-ecampus,merichar/canvas-lms,leftplusrightllc/canvas-lms,landonwilkins/canvas-lms,fronteerio/canvas-lms,loganrun/pincan,AndranikMarkosyan/lms,snehakachroo1/LSI_replica,juoni/canvas-lms,juoni/canvas-lms,sdeleon28/canvas-lms,shidao-fm/canvas-lms,wimemx/Canvas,ShreniiNepal/shrenii_lmp,Unow/ins,Unow/ins,efrj/canvas-lms,AndranikMarkosyan/lms,instructure/canvas-lms,greyhwndz/canvas-lms,redconfetti/canvas-lms,Unow/canvas-lms,shidao-fm/canvas-lms,SwinburneOnline/canvas-lms,matematikk-mooc/canvas-lms,skmezanul/canvas-lms,eCNAP/CANVAS,Jyaasa/canvas-lms,tgroshon/canvas-lms,instructure/canvas-lms,shidao-fm/canvas-lms,merichar/canvas-lms,eCNAP/CANVAS,kyroskoh/canvas-lms,narigone/canvas,arrivu/qibla-ecampus,AndranikMarkosyan/lms,Rvor/canvas-lms,skmezanul/canvas-lms,antoniuslin/canvas-lms,narigone/canvas,antoniuslin/canvas-lms,ShreniiNepal/shrenii_lmp,matematikk-mooc/canvas-lms,djbender/canvas-lms,dgynn/canvas-lms,eCNAP/CANVAS,fronteerio/canvas-lms,HotChalk/canvas-lms,sdeleon28/canvas-lms,usmschuck/canvas,landonwilkins/canvas-lms,Unow/canvas-lms,grahamb/canvas-lms,Jyaasa/canvas-lms,SwinburneOnline/canvas-lms,dgynn/canvas-lms,samuels410/greatlakes-lms,djbender/canvas-lms,jay3126/canvas-lms,Rvor/canvas-lms,usmschuck/canvas,va7map/canvas-lms,usmschuck/canvas,roxolan/canvas-lms,sfu/canvas-lms,landonwilkins/canvas-lms,jay3126/canvas-lms,tgroshon/canvas-lms,shidao-fm/canvas-lms,redconfetti/canvas-lms,efrj/canvas-lms,HotChalk/canvas-lms,leftplusrightllc/canvas-lms,sli7246/canvas_branch,sli7246/canvas_branch,instructure/canvas-lms,samuels410/greatlakes-lms,Rvor/canvas-lms,djbender/canvas-lms,landonwilkins/canvas-lms,wrdsb/canvas-lms,arrivu/jigsaw-lms,kyroskoh/canvas-lms,samuels410/greatlakes-lms,snehakachroo1/LSI_replica,jay3126/canvas-lms,sfu/canvas-lms,utkarshx/canvas-lms,wrdsb/canvas-lms,skmezanul/canvas-lms,gbleydon/canvas-lms,matematikk-mooc/canvas-lms,roxolan/canvas-lms,fronteerio/canvas-lms,AndranikMarkosyan/lms,sdeleon28/canvas-lms,venturehive/canvas-lms,antoniuslin/canvas-lms,Unow/canvas-lms,Unow/ins,whalejasmine/canvas-lms,sfu/canvas-lms,wye0220/shindig-canvas,gbleydon/canvas-lms,wye0220/shindig-canvas,sfu/canvas-lms,jay3126/canvas-lms,wimemx/Canvas,wrdsb/canvas-lms,dgynn/canvas-lms,arrivu/arrivu-lms